Party Caucuses and Coordination: Assessing Caucus Activity and Party Effects

Party caucuses are increasingly important to members' allocation of time. This article reports findings from new data on the minutes, frequency, timing, and attendance of House party caucus meetings. I argue that the party caucuses increasingly affect political and policy information flows to members. This growing party coordination has resulted in a greater bonding and shared strategic information among rank‐and‐file copartisans. This research also contributes to the party effects literature. Earlier research on congressional partisanship has used roll‐call data to measure both member preferences and party effects. I investigate whether or not members' attendance at party caucus meetings immediately prior to key congressional votes imposes partisan cohesion beyond members' preferences. The results indicate that party coordination contributes to greater congressional party unity on key floor votes at both the bill and member level controlling for members' ideological preferences. This party coordination effect occurs even during a period of high intraparty preference homogeneity.